diff --git a/src/redis-shake/common/common.go b/src/redis-shake/common/common.go
index c206e56..8c1e7c8 100644
--- a/src/redis-shake/common/common.go
+++ b/src/redis-shake/common/common.go
@@ -32,6 +32,7 @@ const (
 	TencentCluster = "tencent_cluster"
 	AliyunCluster  = "aliyun_cluster"
 	UCloudCluster  = "ucloud_cluster"
+	CodisCluster   = "codis_cluster"
 
 	CoidsErrMsg = "ERR backend server 'server' not found"
 )
diff --git a/src/redis-shake/rump.go b/src/redis-shake/rump.go
index 2a0bb03..87feac8 100644
--- a/src/redis-shake/rump.go
+++ b/src/redis-shake/rump.go
@@ -178,20 +178,21 @@ func (dr *dbRumper) getNode() (int, error) {
 /*------------------------------------------------------*/
 // one executor(1 db only) link corresponding to one dbRumperExecutor
 type dbRumperExecutor struct {
-	rumperId           int        // father id
-	executorId         int        // current id, also == aliyun cluster node id
-	sourceClient       redis.Conn // source client
-	targetClient       redis.Conn // target client
-	tencentNodeId      string     // tencent cluster node id
-	targetBigKeyClient redis.Conn // target client only used in big key, this is a bit ugly
+	rumperId           int             // father id
+	executorId         int             // current id, also == aliyun cluster node id
+	sourceClient       redis.Conn      // source client
+	targetClient       redis.Conn      // target client
+	tencentNodeId      string          // tencent cluster node id
+	targetBigKeyClient redis.Conn      // target client only used in big key, this is a bit ugly
+	previousDb         int             // store previous db
 
-	keyChan    chan *KeyNode // keyChan is used to communicated between routine1 and routine2
-	resultChan chan *KeyNode // resultChan is used to communicated between routine2 and routine3
+	keyChan            chan *KeyNode   // keyChan is used to communicated between routine1 and routine2
+	resultChan         chan *KeyNode   // resultChan is used to communicated between routine2 and routine3
 
-	scanner   scanner.Scanner // one scanner match one db/proxy
-	fetcherWg sync.WaitGroup
+	scanner            scanner.Scanner // one scanner match one db/proxy
 
-	stat dbRumperExexutorStats
+	fetcherWg          sync.WaitGroup
+	stat               dbRumperExexutorStats
 }
 
 func NewDbRumperExecutor(rumperId, executorId int, sourceClient, targetClient, targetBigKeyClient redis.Conn,
@@ -203,6 +204,7 @@ func NewDbRumperExecutor(rumperId, executorId int, sourceClient, targetClient, t
 		targetClient:       targetClient,
 		tencentNodeId:      tencentNodeId,
 		targetBigKeyClient: targetBigKeyClient,
+		previousDb:         0,
 		stat: dbRumperExexutorStats{
 			minSize: 1 << 30,
 			maxSize: 0,
@@ -453,7 +455,9 @@ func (dre *dbRumperExecutor) getSourceDbList() ([]int32, error) {
 }
 
 func (dre *dbRumperExecutor) doFetch(db int) error {
-	if conf.Options.ScanSpecialCloud != utils.TencentCluster {
+	// some redis type only has db0, so we add this judge
+	if db != dre.previousDb {
+		dre.previousDb = db
 		// send 'select' command to both source and target
 		log.Infof("dbRumper[%v] executor[%v] send source select db", dre.rumperId, dre.executorId)
 		if _, err := dre.sourceClient.Do("select", db); err != nil {